The invention relates generally to wireless sensor networks for patient monitoring and, more particularly, to communication between elements of a wireless patient sensor network.
Monitoring vital signs is an important part of patient care because the general or particular health of the patient is determined, in part, through measurement and interpretation of key physiological indicators. Well-known parameters of patient health include blood pressure, hemoglobin saturation, and features of the electrocardiogram (ECG).
However, the utilization of physiological instrumentation to obtain those measurements at bedside also presents well-known burdens in the clinical environment. The presence of cables, catheters, and tubes connecting the patient and sensors to the instrumentation can diminish productivity and the quality of patient care. For example, rotating a patient to alleviate bedsores or ambulating about the room can be problematic if one is saddled with tethered devices. Procedural delays stemming from cable management also contribute to a greater percentage of time dedicated to routine, mundane tasks not directly related to treatment of the patient's illness.
The longstanding burdens have remained unsolved for a variety of reasons. A major problem involves varying levels of care that one might receive in a hospital. A patient, for instance, may easily progress from low-acuity monitoring at admissions to high acuity monitoring within a specialized care unit, to a lower acuity level involving ordinary cardiac telemetry, and finally to discharge. To meet this need of evolving care, a variety of instrumentation has been developed to accommodate the monitoring needs. These monitoring instruments can be added or subtracted from the patient's monitoring regime, depending on the patient's needs. However, these adaptive needs only add to the burden of cable and device management.
Wireless communication technology leveraged to patient monitoring may at least circumvent some of the problems associated with cable clutter and device management. With instrumentation becoming wireless, management of such devices is eased. In addition, communication with wireless instrumentation/devices greatly reduces the burdens associated with cable management.
Wireless patient monitoring networks, however, bring new problems that are also common to other wireless communication systems. Whether using a wireless patient monitoring network or another wireless communication system, the need to reduce cable clutter often requires that many elements of the network or system be battery powered. This, in turn, brings energy constraints that are not typically seen in wired systems. These constraints increase the need for energy efficient wireless elements and the networks or systems they are a part of.
In addition, not only is there a need for the wireless network or system to function in an energy efficient manner, there is also a need for the system or network to function in a spectrally efficient manner. As the number of wireless communication systems, networks, and/or elements of such systems and networks increases, media access may be limited as operation of one system may interfere with that of another. As such, there is also a need to manage, in a spectrally efficient manner, the operation of multiple systems or networks.
Therefore, it would be desirable to design an apparatus and method that minimizes not only the media access time and energy demand of wireless devices used in wireless systems, but also minimizes the media access time and energy demand of one or more entire wireless systems.